As a seat slide device for sliding a seat, for example, Patent Literature 1 described below discloses a seat slide device for a vehicle including a lower rail fixed to a floor, an upper rail that slides with respect to the lower rail, a lock section that fixes the upper rail to the lower rail, and a movable section (abutting section) provided between the lower rail and the upper rail.
In this seat slide device, when the lock section locks the upper rail and the lower rail, the movable section abuts on a part of the upper rail and a lower rail inner surface, so that rattling of the both is regulated. On the other hand, when the lock section releases locking between the upper rail and the lower rail, the movable section is separated from the lower rail inner surface to suppress sliding resistance, so that sliding of the upper rail with respect to the lower rail is smoothly implemented.